The present invention relates to the refrigeration industry and more particularly, to the field of energy and maintenance efficiency of refrigeration systems.
In a commercial refrigeration apparatus, an evaporator is generally positioned within an interior region of a refrigeration container. For example, in a refrigeration apparatus positioned within a grocery store, e.g., a refrigeration display case having a glass door or an open refrigeration display case having no door, the evaporator is generally positioned along a bottom inner periphery of the refrigeration container. Applicant has recognized that this configuration tends to create numerous maintenance problems such as evaporator accessibility and clogging of drain lines, especially during transitions from defrost cycles. The evaporator positioned within the refrigeration container typically includes intake and output ducts. The configuration of the intake and output ducts, however, also cause maintenance problems in that they become easily clogged with various items that fall to the bottom of the refrigeration container, e.g., price tags and bits of food, during these cycles. Clogged intake and output ducts significantly decrease the efficiency of the refrigeration system.
In the case of walk-in refrigeration units, the evaporator is generally suspended from a top inner periphery of the refrigeration container. Applicant has recognized that condensation from the evaporator generally tends to accumulate especially during frost cycles, presenting various problems including potential health hazards. Another problem that exists with a walk-in refrigeration apparatus having an evaporator suspended from a top inner periphery of the refrigeration container is electrical maintenance. Electrical wiring to and from such evaporators are positioned within the refrigeration container closely adjacent a great deal of condensation which can occur during defrost cycles which often occur three to six times per day, for example, in commercial refrigeration units. The condensation can sometimes cause shorts and other electrical malfunctions, raising another potential hazard. Still another problem that exists with the walk-in refrigeration units is cleanliness and sanitation, i.e., condensation changes from defrost cycles from the suspended evaporators tends to drip onto food and other consumable items stored in the walk-in refrigeration container, causing a serious health risk.
Applicant has also recognized that another problem that commonly exists in a refrigeration apparatus having an evaporator positioned within the refrigeration container is that drain lines tend to freeze when positioned within the refrigeration container. When the condensed liquid in the drain lines freezes, it tends to expand and the drain lines can therefore sometimes burst.
Positioning components of a refrigeration apparatus exterior a refrigeration container is known as can be seen in U.S. Pat. No. 6,070,424 to Bauman et al. titled Modular Refrigeration Unit. Applicant has recognized, however, that the configuration of a condenser and evaporator positioned closely adjacent one another is highly inefficient and is not well suited for commercial applications, such as refrigeration systems for grocery stores. A more energy efficient and low maintenance refrigeration system is still needed.
With the foregoing in mind, the present invention advantageously provides a more efficient refrigeration system and apparatus, a more efficient evaporator apparatus, a refrigeration apparatus conversion kit for converting existing refrigeration apparatuses into more energy and cost efficient refrigeration apparatuses, and associated methods that greatly reduces maintenance needs, enhance energy efficiency, especially during defrost cycles, and reduce various hazards associated with existing refrigeration systems and apparatuses. For example, because an evaporator is removed from the interior of a refrigeration container and placed at a location exterior to and preferably on top of the refrigeration container, significantly less energy is required to defrost or heat the evaporator for the refrigeration container. Because the evaporator is positioned outside of the refrigeration container and preferably in an insulated housing on top of the refrigeration container, less area of the evaporator to heat is required for defrost cycles which can occur about 3-6 times per day, the evaporator then uses much less energy to defrost. Accordingly, for grocery stores or other structures which contain numerous evaporators for refrigeration containers, the energy saving during defrost cycles can be tremendous. The refrigeration system and apparatus of the present invention advantageously identifies the source of the problems associated with sanitation and cleanliness within a refrigeration container, and solves this problem by connecting an evaporator to exterior portions of a refrigeration container. The present invention also advantageously identifies and solves the problem of cleanliness and sanitation with existing refrigeration containers by removing collected condensate from the refrigeration system before it can be introduced to an interior portion of the refrigeration container. By positioning an evaporator on top of a refrigeration container, the difference between discharge air temperature of the cooled air from the evaporator and the ambient inside air temperature of the refrigeration container greatly reduces the accumulation of condensation on exterior surfaces, e.g., bottom, back, or side walls, of the refrigeration container such as a refrigerated display case.
More specifically, the present invention preferably includes a method of reducing energy costs associated with a refrigeration system. The method preferably includes connecting an evaporator to a top outer surface of a refrigeration container so that the evaporator overlies the top outer surface of the refrigeration container, and forming a cool air curtain by removing warm air from an interior upper portion of the refrigeration container and introducing cool air into the interior upper portion of the refrigeration container. The present invention also advantageously includes a method of reducing maintenance costs of a refrigeration system positioned in a grocery store building. The method preferably includes connecting an evaporator to an outer surface of a refrigeration container so that maintenance can be performed on the evaporator without accessing interior portions of the refrigeration container, and providing ready access to the evaporator so that maintenance can be readily conducted on the evaporator unit. The present invention further preferably includes a method of reducing maintenance costs associated with a drain line to remove condensate from an evaporator of a refrigeration apparatus. The method preferably includes positioning a drain pan to underlie an evaporator positioned exterior a refrigeration container to collect the condensate from the evaporator, and connecting a drain line to the drain pan positioned exterior the refrigeration container so that the drain line is positioned exterior the refrigeration container and so that the condensate is removed from the drain pan without freezing.
The present invention advantageously decreases maintenance costs associated with refrigeration system by preventing drain lines from freezing and by eliminating clogs in an evaporator by removing the evaporator from an environment that is quite prone to clogging. The present invention further advantageously enhances the efficiency of an evaporator and greatly reduces the cost of operating and maintaining a refrigeration air handling apparatus.